Translation:Where did I put my booklet and calculator?
Could the translation also be "Where did I put the booklet and my calculator?", or should one know that "booklet and calculator" belong together and are therefore both covered by "שלי"? In that case would "Where did I put the booklet and my calculator?" be "?איפה שמתי את הספרון ואת המחשבון שלי"? Maybe a native speaker or an expert can help me out here. - Thanks.
This is a tough one I think because normally you would attribute the two of them to the world "שלי". I think that normally, if you want to make a distinction that one of these is yours and the other is not, you would not put them in the same sentence together.
What I would say is probably something like: "איפה שמתי את הספרון? ואיפה שמתי את המחשבון שלי" I guess you could also put a comma, and if you make a pause between that would also be understandable:"איפה שמתי את הספרון, והמחשבון שלי?" (not 100% sure about this one).
Another easy way is if you know who the booklet belongs to, then you could just add "שלו/שלה/שלכם" etc. after: "איפה שמתי את הספרון שלו והמחשבון שלי?"